Market standards have varied to some degree since, with a tendency to prefer a paler product than that in vogue, say, six or seven years ago. Moreover, standardised methods of preparation have been introduced, with the result that sheets of a desirably high standard can be produced in from ten to fourteen days, when smoke-curing is conducted only during night hours. Some estates are equipped with smoke-houses which, by continuity of working day and night, provide smoke-dried rubber in from five to six days; but the actual hours of smoke-curing are approximately equal to those of the ordinary type of house. This tendency towards the production of sheets paler in colour than the old standard is probably largely responsible in the present for the commonly observed incidence of surface moulds on stored smoked sheets, and also for some complaints of "under-curing," where the term specifically refers to a failure to dry and cure the rubber thoroughly. Boxes of smoked sheets, which had been stored for varying periods up to five months, were recently inspected, and, in the majority of instances, surface moulds were found to be plentiful. In all cases it was observed that the trouble was intensified where boxes of rubber were stored in contact with cement floors. This "under-curing" is not a question solely of the duration of smoke-drying, although probably the modern practice of curtailing the period has exerted a great influence. To make this clear, it may be stated that, given two batches of uniformly prepared wet sheets, it would be possible to smoke-cure them for equal periods in different houses, so as to produce one batch very much paler in colour than the other, although the total hours of actual smoke-curing would be identical. In order to produce such effects, all that is necessary is to employ different timbers for fuel or different types of furnaces. In the one case there would be produced heat and very little smoke, while in the other the necessary heat would be obtained plus plenty of smoke. The best results naturally are obtained by the employment of the happy medium, and if smoked sheets have to be stored, the ordinary period of smoke-curing should be prolonged to an interval consistent with the capacity of the smoke-house. All precautions taken in preparation and curing can be nullified, as already indicated, by unsuitable storage conditions. TOOL-SHEDS AND STORE-ROOMS.--In some factories it is the rule to see lime, cement, spare rolls, sieves, and a general heterogeneous assortment occupying part of the rubber-drying rooms. The inconvenience is often great; and it certainly seems that these stores and tools are of sufficient value to be accommodated in suitable buildings.